Multiple storage apparatuses are provided, at least part of which are individually incorporated into one of storage groups. Each of multiple control apparatuses is configured to, when assigned one or more of the storage groups each including one or more of the storage apparatuses, control data storage by storing data designating each assigned storage group redundantly in the storage apparatuses of the assigned storage group. An information processing apparatus is configured to, when a storage group with data redundancy being lost is detected, make a change in control apparatus assignment for the storage groups in such a manner that a storage group different from the detected storage group is not assigned to a control apparatus with the detected storage group assigned thereto. Subsequently, the information processing apparatus causes the control apparatus to execute a process of restoring the data redundancy of the detected storage group.